Negative-Temperature State Formed and Interactions Inverted by Symmetric Monocycle Optical Pulse Excitation

Abstract

The excited state dynamics of correlated electron and electron-phonon systems triggered by an oscillating electric-field pulse of large amplitude are theoretically investigated. A "negative-temperature" state and inversion of electron-electron and electron-phonon interactions are induced even by a symmetric monocycle pulse. This fact is numerically demonstrated, using the exact diagonalization method, in a band-insulator phase of one-dimensional three-quarter-filled strongly dimerized extended Peierls-Hubbard and Holstein models. When the total-energy increment is maximized as a function of the electric field amplitude, the occupancy of the bonding and antibonding orbitals is inverted to produce a negative-temperature state. Around this state, the dependences of time-averaged electron-electron and electron-phonon correlation functions on interaction parameters are opposite to those in the ground state.

21 pages, 9 figures, accepted for publication in J. Phys. Soc. Jpn

References in corpus (3)

• Dynamical band flipping in fermionic lattice systems: An ac-field-driven change of the interaction from repulsive to attractive
• Optical freezing of charge motion in an organic conductor
• Coupling-dependent rates of energy transfers from photoexcited Mott insulators to lattice vibrations

Cited by in corpus (3)

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• Optical suppression of electron motion in low-dimensional correlated electron system
• Competition between Interactions and Randomness in Photoinduced Synchronization of Charge Oscillations on a Dimer Lattice